Traumatic Brain Injury Associated with Motorcycle Crashes in Wisconsin, 1991-1997

We evaluated the impact of a variety of motorcycle crash related factors, including crash type, speed limit, highway type, demographics, alcohol involvement and helmet use, on the likelihood of being hospitalized for traumatic brain injury (TBI) and subsequent injury severity and hospital resource utilization. Helmet use was found to have a strong protective effect on the likelihood of TBI across all other factors. Alcohol involvement in the crash was found to increase the probability of TBI, as were higher speed limits and crash configurations increasing the force of impact in a motorcycle crash. However, no explanatory variable had a statistically significant effect on hospital charge or days, or on injury severity once hospitalized. Injuries associated with motorcycle crashes are a major cause of morbidity and mortality in the United States (1). The injury severity and outcomes of a motorcycle crash are more severe than for crashes involving passenger vehicles (2). In 1996-1997 there were 164.1 hospitalizations per 1,000 motorcycle crash drivers and riders as opposed to only 10.6 hospitalizations per 1,000 passenger vehicle occupants in Wisconsin. Similarly, there were 26.0 fatalities per 1,000 Motorcycle crash drivers and riders as opposed to only 1.9 fatalities per 1,000 passenger vehicle occupants. One of the major sources of injuries associated with motorcycle crashes are head injuries (3,4,5,6,7). While studies of motorcycle crash outcomes have consistently shown that helmet use is strongly associated with traumatic brain injuries (TBI) (3,4,5,6,8,9,10,11), few have evaluated the impact of helmet use in the context of crash characteristics, demographic factors and alcohol use. In our study we perform a retrospective cohort study which links together crash and demographic factors with information on he lmet use and alcohol involvement to evaluate several crash outcomes: • Hospitalization with associated traumatic brain injury (and subsequently) ⇒ Average abbreviated injury scores (12) ⇒ Injury severity scores (12) ⇒ Hospital charges ⇒ Hospital length of stay We hypothesize that the lack of helmet use will have a strong impact on the likelihood of TBI, and may effect the other outcomes negatively as well. We also hypothesize that alcohol involvement, older age and crash characteristics which increase the force of impact in a crash (e.g. higher speed limits as a proxy for speed, head on collisions with another vehicle) will positively effect our outcomes.